3. Structural Features(1) Iron coreThe iron core is made of cold rolled grain oriented silicon steel
sheet. Laminations are cut to lengthonGEORG cut to- length line with steplap cut and automatic stacking
functions.The multistep lamination structure can reduce the loss and noise .The steel sheet in the core limbs and yokes are clamped together by
glass-epoxy bonds.(2) WindingHigh quality enameled or paper covered copper is used as conductor,
the winding was made asdrum type, spiral type, improved spiral type, continuous type and
interleaved type to ensure the insulation strength. Standard
tapings are ±2*2.5%of the HV winding.(3) TankThe tank, cover and the conservator are made by corrugated steel
plate .For the small transformers,we use a deep tank and a cover, but for larger transformers, we
manufacture bell type .The corrugated construction are a effective
way for oil cooling.(4) Insulation oilThe tanks are filled with high quality grade mineral oil as per
IEC296 and it is PCB and PCT free.The oil is used to help cooling the transformer. It is also used
provide part of the electrical insulation between internal live
parts.(5) Tap changerTap changers are used to regulate the output voltage of the
transformers to required levels .Weachieve this by changing the ratios of the transformer on the
system by altering the number of turns in the HV winding .Tap
changers can be on load (OLTC) or off load(OCTC).(6) AssemblyThe core and the windings assembled together from the active part
of the transformer. The activebody assembled with multi-windings and identical pressure dry
method adopted, effectively improvedthe electrical strength and the ability to short circuit
withstanding.

4. Test equipment

Strict test should bedone according to IEC standard, by high technical equipments to
ensure thequality and the reliable of every transformer.